\Back\, n. [F. bac: cf. Arm. bak tray, bowl.]
1. A large shallow vat; a cistern, tub, or trough, used by
   brewers, distillers, dyers, picklers, gluemakers, and
   others, for mixing or cooling wort, holding water, hot
   glue, etc.
{Hop back}, {Jack back}, the cistern which receives the
   infusion of malt and hops from the copper.
{Wash back}, a vat in which distillers ferment the wort to
   form wash.
{Water back}, a cistern to hold a supply of water; esp. a
   small cistern at the back of a stove, or a group of pipes
   set in the fire box of a stove or furnace, through which
   water circulates and is heated.
2. A ferryboat. See {Bac}, 1.

\Back\, n. [As b[ae]c, bac; akin to Icel., Sw., & LG. bak,
Dan. bag; cf. OHG. bahho ham, Skr. bhaj to turn, OSlav. b?g?
flight. Cf. {Bacon}.]
1. In human beings, the hinder part of the body, extending
   from the neck to the end of the spine; in other animals,
   that part of the body which corresponds most nearly to
   such part of a human being; as, the back of a horse, fish,
   or lobster.
2. An extended upper part, as of a mountain or ridge.
         [The mountains] their broad bare backs upheave Into
         the clouds.                           --Milton.
3. The outward or upper part of a thing, as opposed to the
   inner or lower part; as, the back of the hand, the back of
   the foot, the back of a hand rail.
         Methought Love pitying me, when he saw this, Gave me
         your hands, the backs and palms to kiss. --Donne.
4. The part opposed to the front; the hinder or rear part of
   a thing; as, the back of a book; the back of an army; the
   back of a chimney.
5. The part opposite to, or most remote from, that which
   fronts the speaker or actor; or the part out of sight, or
   not generally seen; as, the back of an island, of a hill,
   or of a village.
6. The part of a cutting tool on the opposite side from its
   edge; as, the back of a knife, or of a saw.
7. A support or resource in reserve.
         This project Should have a back or second, that
         might hold, If this should blast in proof. --Shak.
8. (Naut.) The keel and keelson of a ship.
9. (Mining) The upper part of a lode, or the roof of a
   horizontal underground passage.
10. A garment for the back; hence, clothing.
          A bak to walken inne by daylight.    --Chaucer.
{Behind one's back}, when one is absent; without one's
   knowledge; as, to ridicule a person behind his back.
{Full back}, {Half back}, {Quarter back} (Football), players
   stationed behind those in the front line.
{To be or lie on one's back}, to be helpless.
{To put}, {or get}, {one's back up}, to assume an attitude of
   obstinate resistance (from the action of a cat when
   attacked.). [Colloq.]
{To see the back of}, to get rid of.
{To turn the back}, to go away; to flee.
{To turn the back on one}, to forsake or neglect him.

\Back\, a.
1. Being at the back or in the rear; distant; remote; as, the
   back door; back settlements.
2. Being in arrear; overdue; as, back rent.
3. Moving or operating backward; as, back action.
{Back charges}, charges brought forward after an account has
   been made up.
{Back filling} (Arch.), the mass of materials used in filling
   up the space between two walls, or between the inner and
   outer faces of a wall, or upon the haunches of an arch or
   vault.
{Back pressure}. (Steam Engine) See under {Pressure}.
{Back rest}, a guide attached to the slide rest of a lathe,
   and placed in contact with the work, to steady it in
   turning.
{Back slang}, a kind of slang in which every word is written
   or pronounced backwards; as, nam for man.
{Back stairs}, stairs in the back part of a house; private
   stairs. Also used adjectively. See {Back stairs},
   {Backstairs}, and {Backstair}, in the Vocabulary.
{Back step} (Mil.), the retrograde movement of a man or body
   of men, without changing front.
{Back stream}, a current running against the main current of
   a stream; an eddy.
{To take the back track}, to retrace one's steps; to retreat.
   [Colloq.]

\Back\, v. i. [imp. & p. p. {Backed}; p. pr. & vb. n.
{Backing}.]
1. To get upon the back of; to mount.
         I will back him [a horse] straight.   --Shak.
2. To place or seat upon the back. [R.]
         Great Jupiter, upon his eagle backed, Appeared to
         me.                                   --Shak.
3. To drive or force backward; to cause to retreat or recede;
   as, to back oxen.
4. To make a back for; to furnish with a back; as, to back
   books.
5. To adjoin behind; to be at the back of.
         A garden . . . with a vineyard backed. --Shak.
         The chalk cliffs which back the beach. --Huxley.
6. To write upon the back of; as, to back a letter; to
   indorse; as, to back a note or legal document.
7. To support; to maintain; to second or strengthen by aid or
   influence; as, to back a friend. ``Parliament would be
   backed by the people.'' --Macaulay.
         Have still found it necessary to back and fortify
         their laws with rewards and punishments. --South.
         The mate backed the captain manfully. --Blackw. Mag.
8. To bet on the success of; -- as, to back a race horse.
{To back an anchor} (Naut.), to lay down a small anchor ahead
   of a large one, the cable of the small one being fastened
   to the crown of the large one.
{To back the field}, in horse racing, to bet against a
   particular horse or horses, that some one of all the other
   horses, collectively designated ``the field'', will win.
{To back the oars}, to row backward with the oars.
{To back a rope}, to put on a preventer.
{To back the sails}, to arrange them so as to cause the ship
   to move astern.
{To back up}, to support; to sustain; as, to back up one's
   friends.
{To back a warrant} (Law), is for a justice of the peace, in
   the county where the warrant is to be executed, to sign or
   indorse a warrant, issued in another county, to apprehend
   an offender.
{To back water} (Naut.), to reverse the action of the oars,
   paddles, or propeller, so as to force the boat or ship
   backward.

\Back\, v. i.
1. To move or go backward; as, the horse refuses to back.
2. (Naut.) To change from one quarter to another by a course
   opposite to that of the sun; -- used of the wind.
3. (Sporting) To stand still behind another dog which has
   pointed; -- said of a dog. [Eng.]
{To back and fill}, to manage the sails of a ship so that the
   wind strikes them alternately in front and behind, in
   order to keep the ship in the middle of a river or channel
   while the current or tide carries the vessel against the
   wind. Hence: (Fig.) To take opposite positions
   alternately; to assert and deny. [Colloq.]
{To back out}, {To back down}, to retreat or withdraw from a
   promise, engagement, or contest; to recede. [Colloq.]
         Cleon at first . . . was willing to go; but, finding
         that he [Nicias] was in earnest, he tried to back
         out.                                  --Jowett
                                               (Thucyd. )

\Back\, adv. [Shortened from aback.]
1. In, to, or toward, the rear; as, to stand back; to step
   back.
2. To the place from which one came; to the place or person
   from which something is taken or derived; as, to go back
   for something left behind; to go back to one's native
   place; to put a book back after reading it.
3. To a former state, condition, or station; as, to go back
   to private life; to go back to barbarism.
4. (Of time) In times past; ago. ``Sixty or seventy years
   back.'' --Gladstone.
5. Away from contact; by reverse movement.
         The angel of the Lord . . . came, and rolled back
         the stone from the door.              --Matt. xxvii.
                                               2.
6. In concealment or reserve; in one's own possession; as, to
   keep back the truth; to keep back part of the money due to
   another.
7. In a state of restraint or hindrance.
         The Lord hath kept thee back from honor. --Numb.
                                               xxiv. 11.
8. In return, repayment, or requital.
         What have I to give you back!         --Shak.
9. In withdrawal from a statement, promise, or undertaking;
   as, he took back0 the offensive words.
10. In arrear; as, to be back in one's rent. [Colloq.]
{Back and forth}, backwards and forwards; to and fro.
{To go back on}, to turn back from; to abandon; to betray;
   as, to go back on a friend; to go back on one's
   professions. [Colloq.]